Internal combustion engine



Oct. 26-, 1937. J, LAE KE 2,096,814

INTERNAL COMBUSTION ENGINE Filed Feb. 3, 1937 Patented a. 26, 1937- UNITED STATES 2,096,814 7 INTERNAL COMBUSTION ENGINE Jean Laessker, Arbon, Switzerland, assignor to Societe Anonyme" Adolphe Saurer,

Arbol'l,

Switzerland, a corporation of Switzerland Application February a, 1931, Serial No. 123,766 In Germany March 2, 1936 3 Claims.

The closing motion of the valve stem or of an injection nozzle for internal combustion engines is as a rule efiected by a spring, the end of which, acting on the valve stem, bears against an abut- 5. ment sleeve which is threaded on the valve stem. This is the case more particularly in so-called disc or plate nozzles, in which a disc at the end of the nozzle needle or valve stem closes the outlet openlng for the vfuel.

In each closing operation the valve disc, under the influence of the closing spring, strikes against the end of the nozzle body surrounding the fuel outlet opening. The stress due to impact'thus caused is transmitted by the nozzle needle or 15 valve stem to the thread by which the abutment sleeve is fixed on the upper end of the valve stem. Under the influence of these continuously repeated impacts the thread of the abutment sleeve or of the valve stem becomes loose, more particu- 0 larly since the thread convolutions on the abutment sleeve and the valve stem bear against one another on one side only, owing to the action of the very powerful closing spring. This disadvantage is particularly noticeable when the valve 25 plate or disc and the nozzle or valve stem are of small dimensions which must be adhered to if these parts are accommodated in the interior of a filter body inserted in the nozzle body. When the mutual engagement of the threads provided 30 on the one hand on the abutment sleeve and on By the present invention this disadvantage is overcome by making the abutment sleeve substantially of two coacting parts, of which one part which carries the internal thread which co- 7 0 acts with the thread of the valve stem, is resiliently compressible in a direction transverse to the longitudinal axis of the valve stem, tapers conically in a direction opposite to the direction of pressure of the closing spring, and lies in a corresponding hollow conical recess of the other part of the abutment sleeve, against which the closing spring bears. By this construction the stripping oi the thread convolutions referred to above is with certainty avoided, for through the wedg- 0 ing action of the coacting conical surfaces of the two parts of the sleeve and through the force of the closing spring the resiliently compressible part of the sleeve is pressed with its internal thread so firmly against the thread of the valve 55 stem that the two threads, external and internal,

always hear firmly against one another. Stripping of the thread is thus definitely prevented.

The invention will be more fully described hereinafter with reference to the accompanying drawing, in which is illustrated a constructional 5 example and in which:

'Figure 1 shows the improved injection nomle partly in longitudinal section, while in Figures 2 and 3 the spring abutment sleeve is shown in longitudinal section and in plan view on a larger scale.

The nozzle body I is disposed in a chamber I,

which is provided in the cylinder head 2 of the internal combustion engine, and is closed at its upper end by a screw plug 3, the nozzle body being connected by an internally threaded and shouldered sleeve 5 in a fluid-tight manner with the nozzle head 6. The lower end of the nozzle head 6 extends as usual somewhat into the'cylinder space of the internal combustion engine. The fuel is supplied through a pipe I! which is in communication with the upper end of the nomle body. 1

The nozzle body I has a longitudinal bore .ln which a filter body. I! is disposed. This filter'25 body is formed in known manner with external longitudinal grooves, through which the fuel passes during the filtering process. The filtered fuel then passes through fine openings ll provided in the lower part of the filter body lnto a cavity l5 within the filter body, into which extends the upper end of the stem it of the nozzle plate or valve disc II, the valve stem being as usual movable longitudinally in the nozzle head G. This valve disc ll normally closes the outlet opening for the fuel provided at lower end oi the nozzle headnl, V r The valve disc I! is held in the closed position by a spring I! which is disposed in the cavity II in the filter body and bears at one end against 40 the nozzle head 6 and at the other end against a handofapart lQadaptedtobethreadedonthe upper end of the stem Ii and on the other hand of a sleeve-like part 2| which coasts with the said threaded part. As shown more particularly in Pig. 2. the

threaded part I! is provided with two slots II and 22 which extend in the longitudinal direction of the stem l8 and of which the slot 2| extends over the entire height of the threaded part, whereas the slot 22 extends over only a portion of the entire height, so that a bridge 22 is formed, which interconnects the two halves of the threaded part H, which are formed by the slots 2i and 22. Owing to the provision of the two slots 2| and 22,

a the threaded part can be resiliently compressed transversely to the longitudinal axis of the stem It. The part I! of the sleeve is conically tapered externally in opposition to the direction of pres-.

sure of the closing spring I8 and lies in a corresponding internally conical bore 24 of the second sleeve-like part 20 of the abutment, against the lower edge of which the upper end ofthe closing spring l8 bears. Under theaction of the closing spring the outer sleeve-like part 20 of the abutment is forced upwards, with the result that the resilient threaded part I9 is pressed with its internal thread firmly against the external thread provided at the upper end of the stem l6. By this meansand owing to the wedging action of the coacting conical surfaces of the two parts l9 and 20 of the abutment the two of the threaded surfaces provided on the one hand in the part IQ of the spring plate and on the other hand on the upper end of the stem l6 arecaused always to bear firmly against one another. Any stripping of these threads under the influence of the impacts which are continuously repeated at each closing motion is thereby prevented with certainty. It will be observed that the part 20 is movable longitudinally to a limited degree with respect to the part I! under the influence of the spring I 8 and that by reason of such movement and the coacting' conical surfaces of the two parts, the part l9, being resilient, is compressed about the stem l6 and its internal thread is 40 pressed firmly against the external thread at the nozzle head, a threaded valve stem movable longitudinally, a valve carried by the valve stem and arranged to cooperate with the nozzle head, a spring abutment sleeve consisting of two coacting parts, of which one part is threaded internally for engagement with the valve stem, is resiliently compressible in a direction transverse to the longitudinal axis of the valve stem, and is conically tapered externally toward the valve, and the other part of which is movable longitudinally with respect to the first named part and is conicaily tapered internally to cooperate with the first named "longitudinally and is thereby resiliently compressible in a direction transverse to the longitudinal axis of the valve stem, and is conically tapered externally toward the valve, and the other part of which is movable longitudinally with respect to the first named part and is conically tapered internally to cooperate with the first named part, and a closing spring which bears against the second named part.

3. In an injection nozzle for internal combustion engines, the combination of a nozzle, a nozzle head, a threaded valve stem movable longitudinally, a valve carried by the valve stem and arranged to cooperate with the nozzle head, a spring abutment sleeve consisting of two coacting parts, of which one part is threaded internally for engagement with the valve stem, and is itself formed of a plurality of parts divided longitudinally and connected at one point by a bridge piece, and is thereby resiliently compressible in a direction transverse to the longitudinal axis of the valve stem, and is conically tapered externally toward the valve, and the other part oi! which is movable longitudinally with respect to the first named part and is conically tapered internally to cooperate with the first named part, and a closing spring which bears against the second named part.

JEAN LAESSKER. 

